A native of the sea cliffs, quarries and old
walls of southern Europe, hence its common name.
One of the best loved of plants, the Wallflower
is really a perennial, but usually treated as
a biennial.
The plant is of bushy erect habit, one to two
feet high, with fragrant flowers, about an inch
across, yellow or brownish-yellow in the type,
but varying from off-white to pink, terra-cotta,
orange, scarlet and crimson in varieties of garden
origin Chieranthus allionii, a native of North America,
is called the Siberian Wallflower, and is Erysimum
asperum to botanists.

Reaching a height of nine inches, its heads of
bright orange flowers in late spring are welcome
successors to the true Wallflower. There is also
a pretty mauve-flowered form known as Chieranthus linifolius
(syn. Erysimum linifolium).

Seed should be sown in the open in July and the
seedlings planted in their permanent positions
by October.

Propagation is from seed.

The flowering season is from March to May for
Chieranthus cheiri and in May and June for Chieranthus allionii.

Wallflower
Hardy Perennial.
One to two feet.
Flowers of several colours, February to May.

Wallflowers are absolutely essential to any sort
of spring gardening, both for their colour and
smell, and more care should be given to their
provision than is usually allowed.

The Wallflower
is nominally a perennial, and sometimes plants
will survive several seasons, and form large and
handsome bushes; but for a dependable show of
flowers every year and particularly where beds
are filled with Wallflowers for spring blooming,
it is essential that it should be treated as a
biennial, and raised freshly every year. Seed
should be sown in drills half an inch deep, and
six inches apart, not later than the middle of
June. The soil should be in nice friable condition,
but need not be all that rich. If great heat and
drought follow the sowing, shade the bed with
mats. The seedlings will appear in a few days;
keep down weeds, and hoe between the drills. About
the middle of July catch, if possible, a showery
time, and plant out the seedlings on good, sound
soil in an open position, using a trowel, and
keeping as much soil on the root-fibres as is
practicable. In this bed the plants should be
in rows a foot apart every way. Keep the ground
clean and open until October, when the Wallflowers
may be removed to their spring quarters, again
getting up the roots with as little disturbance
as possible. At this last move the plants should
be set quite close, touching each other all round.

A properly grown Wallflower plant at this stage
ought to be compact and stout, from a foot to
eighteen inches high and as much through; the
three-inch specimens with about a dozen leaves
which are often seen as spring bedding-stuff,
are miserable impostors.
The reason why most biennials – such as
Wallflowers, Canterbury
Bells and Sweet
Williams ought to be large and stout by planting
time is that as a rule they spend all their energies,
when the spring arrives, on preparations for flowering;
the plant, whatever its size, starts towards blooming
at once, and spends little more tissue in building
up its stature.

All biennials should be given as long a season
of growth as possible in the old year, and encouraged
to build up big, strong frames for the next year’s
display.

The soil for Wallflower beds should be clean and
sound, but needs no manure; of course, where plants
are grown in constant succession the ground must
be refreshed; leaf-mould and wood-ashes are the
best form of addition. The plants may be put out
in groups in mixed borders, in lines at the sides
of paths, or in masses in any beds that are available.
For the latter, separate colours should be kept
together.

These are all single-flowered.
The double varieties are quite different in character,
having straight spikes of close-set rosettes much
like a Ten-Week Stock.
The German or Rocket produces a solitary
spike; the Dwarf Branching is more compact, with
several spikes. The colours comprise several shades
of brown, pinkish purple, clear yellow and creamy
white.

In all ordinary climates the Wallflower may be
called quite hardy; but in severe winters of long-continued
frost it may succumb. Wallflowers are liable to
a disease in the root allied to the “finger
and toes” or “club root” of
the Brassica tribe. Plants affected generally
droop and turn yellow; they should be pulled up
at once and burnt. Wallflowers will droop their
leaves when in full health, on sunny and windy
mornings after a frosty night; this symptom must,
of course, be distinguished from the permanent
sickliness of injured root-action.

A beautiful spring medley may be produced by planting
the lighter coloured Wallflowers hap-hazardly
with Forget-me-not,
Silene pendula and Primroses.
A rough corner furnished in this way will sometimes
put a man out of conceit with his more formal
and ambitious designs. In such a place a few of
the strongest Wallflowers may be left for another
season; but all others should be forked up and
burnt directly they are out of flower, as the
smell of stale Wallflowers is grievous.

The beds
where they have stood must be thoroughly dug,
manured and moistened before anything else is
planted in them; nothing takes the goodness out
of mould and dries it up so completely as Wallflower
roots.